221297408655 has 16 divisors (see below), whose sum is σ = 354253561440. Its totient is φ = 117966048768.

The previous prime is 221297408653. The next prime is 221297408699. The reversal of 221297408655 is 556804792122.

It is not a de Polignac number, because 221297408655 - 2¹ = 221297408653 is a prime.

It is a junction number, because it is equal to n+sod(n) for n = 221297408598 and 221297408607.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (221297408653) by changing a digit.

It is a polite number, since it can be written in 15 ways as a sum of consecutive naturals, for example, 3671350 + ... + 3731139.

It is an arithmetic number, because the mean of its divisors is an integer number (22140847590).

Almost surely, 2^221297408655 is an apocalyptic number.

221297408655 is a deficient number, since it is larger than the sum of its proper divisors (132956152785).

221297408655 is a wasteful number, since it uses less digits than its factorization.

221297408655 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 7404490.

The product of its (nonzero) digits is 2419200, while the sum is 51.

The spelling of 221297408655 in words is "two hundred twenty-one billion, two hundred ninety-seven million, four hundred eight thousand, six hundred fifty-five".